General approach to efficient implementation of 2-D denominator-separable digital transfer functions

A functional theoretical framework is reported for obtaining efficient 2-D digital filter realisations. A given 2-D transfer function having a separable denominator polynomial is developed into certain expansions which may be realised as two-stage structures. In such structures, only suitable 1-D substructures need to be searched for to obtain a complete realisation by connecting 1-D substructures using the corresponding weighting matrix.